Control mechanism



C. T. MASON CONTROL MECHANISM April 3, 1928. 1,664,459

INVENTOR Cfiages Maw/7' ATTORNEY vide a control mechanism that tuated inresponse to a relatively slight slip movement or lost motion betweendriving and driven members and a novel means for 'tions against PatentedApr. 3, 1928.

1,664,459 NITED STATES PATENT OFFICE.

CHARLES THOMAS MASON, or SUMTEB, sou'rn caaomna CONTROL MECHANISM.

Application filed March 28, 1922. Serial No. 547,594.

My invention relates to control mechanisms and particularly tomechanisms for controlling electrically-operated refrigerating machines.

, One object of my invention is to provide a device of the aboveindicated character that shall be simple and durable in construction andeffective in operation.

Another object of my invention is to provide a control mechanism whichshall be so actuated by a relatively powerful moving member andcontrolled by a comparatively delicate thermo-responsive or othermechanism as to ensure greater reliability and more positive action thanis usual with many delicate thermo-responsive control devices. Anotherobject ofmy invention is to proutilizing such" movement.

Another object of my invention is to provide a mecahnism for member thatshall be of positions and biased in different direcits latched positionsby a single means. I

lVith such objects in view, as Well as other advantages whichniay beincident to the utilization of the improvements, the invention consistsin the parts and combinations thereof hereinafter set forth and claimed,

with the understanding that the several'nee type comprises condensingand expansion chambers, known as the high and low pressure sides of themachine. In a refrigerator of the rotary compressor type, a compressor,driven by an electric motor, is adapted,

to draw off evaporated refrigerant from the expansion chamber and todeliver the same to the condensing chamber in a state of highcompression. lVater conducting coollVhen this shall be acoperating acontrolf latched in a plurality operated refrigerating machine will bein the compressed refrigerant g tubes, in the condensing chamber, causeto so condense as to form a body of refrigerating liquid.

liquid reaches afloat valve releases some of it to the expansionchamber, pansion absorbs heat from medium.

It is desirable, machines, to have tomatically responsive to certainlevel. a for conduction wherein its exthe surrounding in certainrefrigerating the operation thereof aucertain high and low temperaturelimits but, as is also known to those versed in the art, temperaturerespnsive mechaisms are usually delicate and not adapted to directlypositively actuate Pother relatively heavy, mechanisms or parts withaccuracy and precision.

It is my aim to nism that shall be provide a control mechaaccuratelyresponsive to precise temperature limits, that shall be effeetive tooperate relativelyheavy moving parts and that shall be of such simpleand economical construction as to conserve space, ensure continuedservice and-to render more effective the operation of the machine ordevice controlledthereby;

In practicing ing and driven members, and compressor shafts, of amachine, as above described.

my invention, I provide a 'slip or lost motion connection betweendrivsuch as the motor 7 refrigerating Thedost or slip motion of thisconnection is utilized in the starting and stopping of the motor, tooperate a switch in the motor circuit and to operate certain valves forcontrolling the operation of a refrigerator or other device. Theoperation of the switch is controlled by nism which is,

temperature changes occur.

a delicate latching mechain turn, controlled by a thermo-i-esponsivedevice disposed in a refrigera-tor or adjacent to other means whereinThus, through the medium of a delicately actuated device,

a relatively heavy member may with suflicient tively actuate the same.

be supplied force to accurately and posi- In order to make the inventionmore clearly understood, means are shown in the accompanying drawingsfor carrying the same into practical effect, without limiting theimprovements,

in their useful applcations, to the particular constructions, which forthe purpose of explanation, are made the subject of illustration.

7 Figure 1, of the accompanying drawings, 1

r ameans 15, such as full is a semi.rdiagrammatic structural view'of acontrol mechanism embodying my invention, showing, structurally, theadjacent ends of driving and driven members or shafts and the lost orslip-mot-ion mechanism thereof and showing, diagrammatically, thecooperating switch, valves and thei no-responsive device therefor.

Fig. 2 is a view, partially in section and partially in elevation of thestructural parts of Fig. 1, with a portion of a motor for the drivingshaft shown diagrammatically,

3 is a view taken along the line Ill III of Fig. 2 and i Fig. 4: is anend view of the device shown in Fig. 2, as viewed in the direction ofthe arrow IV.

A control mechanism of my invention comprises, in general, a drivingmember or shaft 2, such as the shaft of an electric motor 5, a drivenmember or shaft 3, as of rotary compressor, a flexible coupling 1- forjoinins the shafts 2 and 3 through a slip connection device 6 thatconvertstorsional slip movement between the shafts 2 V and 3 intolongitudinal or axial movement with respect to the shafts, meanscomprisa main operating lever 7 responsive to rotative movement of thedriving and driven members 2 and 3, respectively through the device 6,plurality of control devices or valves9 connected tothe lever 7, acontrol device or SWllLCl1111GCllfl11lSln 10, a latch device 12, athermoresponsive device 14 and the refrigerating chamher or brine tanlrof a refrigerating device. for actuating the thermo-responsive device14:.

oil

The movement-converting device 8 comprises a collar or ring 17 securedtothe driving shaft 2, as by a screw 18, and a collar 20 that isturnable relative to tie shaft 2 about the axis thereof. 7 H

The collars 17 and 20 are provided-in the adjacent transverse engagingsurfaces thereof, with av plurality of longitudinally oppositelyregistering pockets or recesses 21. These pockets, being similar, areall shown only in connection with the collar 20, as more clearlyillustrated in Fig. 3. Each oppositely registering pair 'of the pockets21 adapted to so receive a ball 22 therein as to closely encompass thesame when the shafts 2 and 3 are-stationary. as shown in the drawings.Each slot 21, also, slopes for a certain distance, in a direction aroundthe shaft 2, from one end of the slot which is of a depth substantiallyequal to a radius of the ball 22 therein. to the surface of the ring 17or 20 in which it is disposed. The direction of slope is determined bythe .direction of rotation of the shafts and is also such, in thepockets of each pa r, that, when the shafts 2 and turn relatively, theball therein will move toward the adjacent surfaces of the collars 17and 20. Thus, in response to such relative turning movement, the collar20 is moved away fromthe collar 17 along the shaft 2 until it engages aring or plate 24 constituting a part of the flexible coupling l. 'lhedistance of movement of the collar 20 is less than the diameterof thehalls 22 to prevent the latter escaping from the pockets 21. Thecoupling 4 further comprises a plate25 secured to the shaft 3, as

by a set screw 26 in a sleeve portion 27 thereof, and is provided withdiametrically 0pposite openings 28 therethrough. A flexible disk orplate 30 disposed between the plates 24; and 25, is secured to the plateat by bolts 31 that extend, at one end, into the openings 23. The latterare sufliciently larger than the heads of the bolts 31 to permit aslight torsional movement between the plates 25 and 30. The plate 24: isprovided with dianietriCally-opposite openings, not shown, similar tothe openings-28 that are angularly displaced 90 from the openings 28 andin which the plates 30 and 25, are disposed.

lhe collar 20 is provided with an annular or perimetral groove orchannel 33, inits outer surface and has an annular recess 34 and anannular shoulder 35 therein. A helical spring 36 surrounds the shaft 2,inthe recess 3%,and presses oppositely against the shoulder 35 and the[collar 24 to move the collar 20 against the collar 17 when the devic.comes to rest. The plate 24, turnably mounted on the shaft 2, has anannular portion 38, constituting a shoulder, which bears on the shaft 2,and a central opening in which a ring 39 is disposed. The latter,constituting an outer ball race in which balls 40 are disposed, hearsagainst the shoulder 38 to hold he plate 2st. in position. The ring 39and the balls lOare in turn held in position by a ring 4-11,

constituting an inner ball race, and headed screw 42 extendingcentrallyinto the end of the shaft 2. V

Longitudinally extending pins 44, secured. to the plate 2 project intoopenings 4:5 in the collar 20 that are symmetrically disposed about theshaft'2 between the groove 33 and the recess 34. V

The main operating lever 7 comprises a yoke portion 4L7 having pins 48extending into the channel 33, on diametrically opposite sides of thecollar 20, and is pivoted on a pin 49; Ehe lever 7 further comprises anarm 50 that is pivotally connected. By pins '52 and 53, to oppositelylongitudinally extending links 54 and 55, respectively. The linlr isconnected to operating arms or levers 56 of the control devices orvalves 9. The latter, while merely illustrative of any control devicethat may be operated by he lever 7 may be utilized to control the watersupply of a refrigerator condensing heads of bolts 32, joining the llll)chamber, to open and close the suction line between the expansionchamber and the compressor and to start and stop the flow of refrigerantfrom the condensing to the expansion chambers thereof.

The control mechanism or switch device 10 comprises movable andstationary contact members 58 and 59, respectively, that are connectedin the circuit of the motor 5 for driving the shaft 2 or to otherdevice.

The movable contact member 58 is preferably mounted, through a resilientarm or strip 60 and an insulating member 61, on a lever 62 that ispivoted on a pin 63. The lever 62 is provided, at one end, withoppositely inclined cam surfaces 65 and 66 and is adapted to movebetween stationary pins 67 and 68 adjacent to its other end.

The latch device 12 comprises a pair of pawls or dogs 70 and 71,pivotally mounted on a pin 72, that have spaced parallel arms 73 and 74and latching arms 75 and 76, re-

spectively. The arms 75 and 76 extend, in directions,

opposite IBliItlWB overlapping from the pin 72, to positions adjacent tothe limiting positions of the lever 62, to engage and latch the latterin said positions. A roller 78, mounted at the outer end of the link 54by a pin 79, is biased against one end of the lever 62 by a spring 80that extends between a stationary pin 81 and a pin 82 on the link 54 andconstitutes energystoring means for actuating the lever '62.

The thermo-responsive device 14 comprises a container or bulb 84disposedin a refrigerator 85 and connected, by a tube 86, to a fixed orstationary end 87 of a bellows device 88.

The bulb 84, the tube 86 and the bellows 88 constitute a closed systemthat is charged with methyl chloride or other suitable inaterial havinga vapor pressure sensitively responsive to ten'iperature changes. A rod90 is connected, at one end, to the longi tudinally movable end 91 ofthe bellows device 88 and,.at its other end, by a pin 92, to one arm 93of a bell crank lever 94 that is pivoted to a. fixed pivot pin 96 andhasits other arm 97 screw threaded or otherwise constructed to receivean adjustable weight member 98.

In operation, the parts assume the positions shown in the drawings, whenthe shaft 2 is at rest. Under this condition, in a refrigeratingmachine, the temperature in the refrigerating chamber or brine tank 85gradually rises and the vapor pressure of the methyl chloride increasesto expand the bellows device 88. During this expansion, the rod 90 ismoved to the right, and, in turn, moves the bell crank lever 94, incounterclockwise direction, against the action of the weight member 98.The latter may be adjusted along the arm 97 to cause the proper movementof the lever 94 in response to any the roller 78 to move along the camsurface 66 and to thereby move the lever 62 in the clockwise directionto engage the contact 'members 58 and 59 and to start the motor of theshaft 2. During this movement, the lever 62 engages and is latched by,the arm 75, of the pawl 70. lVhen the shaft 2 lo tates, the slopingsurfaces of the pockets 21, in the collars 17 and 20, move oppositelywith respect to the balls 22 and the latter force the collar 20 alongthe shaft 2 against the action of the spring 36. This movement causesthe pin 48 in the channel 33 to move the lever 7 clockwise about itspivot pin 49 to operate the valves 9 and to move the roller 78downwardly along the cam surface 66 and around the end of the lever 62to position opposite the cam surface 65 thereof.

When the temperature in the bulb 84 falls to a predetermined point, thebellows device 88 contracts to move the. arm 90 to the left. This actioncauses the arm 93 to engage the arm 7 3 of the pawl 70 and to disengagethe arm 75 from the end of the lever 62. Thus released, the lever 62 ismoved counter-clockwise by the roller 78 which is moved -up Wardly, bythe spring 80, against the cam surface 65.

Counter-clockwise movement of the lever 62 disengages the contactmembers 58 and 59 to stop the motor and to thus, cause the collar 20 tomove to the left, when the shaft 2 ceases to rotate. The above actionscause the lever 62 to become again latched by the arm 76, in itsleft-hand position, and to move the roller 7 8 to the right, into theposition shown in the drawings. The above cycle of operation may berepeated automatically in response to rise and fall of the temperatureof the bulb 84.

The control mechanism of my invention is extremely simple inconstruction and operation, economical to i'naintain and very positiveand accurate in its response to specific temperature values.

I claim as my invention:

1. In a control mechanism, the combination with driving and drivenmembers having a slip connection therebetween, of control means, meansresponsive to ,relative movement of the driving and driven members foractuating said control means to operative and inoperative positions, andautomatically-releasable means for locking said control means in saidpositions.

2. In a control mechanism, the combination with driving and drivenmembers hav- All ing a slip connection therebetween, of control means,means responsive to relative movement of the driving and driven membersfor storing potential energy, and means for releasing said energy toactuate said control means. 1

A control mechanism for a refrigerating machine, con'iprising a motorshaft, a compressor shaft driven thereby, said shafts being disposed inend-to-end axial alignment having limited relative angular movement,means for controlling one of the operations of the machine, and meansresponsive to relative movement between the motor and compressorshaftsfor actuating said control means.

A control mechanism for a refrigerating machine, comprising a movablemotor element, a member driven thereby having limited movement relativethereto, a switch for controlling the operation of themotor element, alatch mechanism for said switch, means responsive to relative movementbetween he motor and the driven member for storin energy to actuate saidswitch, and temperature-responsive means for releasing said latchmechanism.

5. In a control mechanism, the combination with driving and drivenmembers having a slip connection. therebetween, of a control device,means responsive to relative movement of the driving and driven mem'bers for storing energy to actuate the control device, means for holdingthe control device against said sponsive means for releasing saidholding means. 7

6. In a control mechanism, the combination with driving and drivenmembers having a slip connnection therebetween, of a control device,means responsive to relative movement of the driving and driven memhersfor storing energy to actuate the con trol device, means for holding thecontrol device against said energy-storing means in a plurality ofpositions, and thermo-responsive means for releasing said holding meansfrom said positions.

7. In a control mcchanisn'i, the combination with a-Xiallyaligneddriving and driven shaft members having limited relative movementtherebetween, of a control device, potential energy-storing meansincluding a spring for actuating the control device, and means connectedbetween the driving and driven members and responsive to relativemovement thereof for storing energy in said storing means.

8. In a control mechanism, the combination with driving and drivenmembers having a slip connection therebetween, of a control device,energy-storing means responsive to relative movement of the driving anddriven members for actuating the control device, and thermo-responsivemeans for restored energy, and thermo-releasing said energy to actuatethe control device.

9. In a control mechanism, the combination with driving and drivenmembers having a slip connection therebetween, of a con trol device,means responsive to relative movement of the driving and driven mem bersfor storing energy to actuate the control device, means for holding thecontrol device against actuation by the energy-storing means, andthermo-responsive means for releasing the holding means.

10. A control mechanism for a refrigerating machine, comprising amovable motor element, a member driven thereby having limited movementrelative thereto, a switch for controlling the operation of the motorelement, a latch mechanism for holding said switch in its open andclosed positions, means responsive to relative movement be tween themotor element and the driven member for storing energy to open and closesaid switch, and temperature-responsive means for releasing said latchmechanism.

11. A mechanism for controlling operation of a refrigerating machine,comprising a control member movable in reverse directions between openand closed positions means for latching the same in each of saidpositions, a motor and means actuated thereby for biasing the controlmember away from each of its latchedpositions.

12. A mechanism for controlling operation of a refrigerating machine,comprising a control member movable in reverse directions between openand closed positions, means for latching the same in each of saidpositions, a motor, means actuated thereby for biasing the controlmember away from each of its latched positions and thermoresponsivemeans for actuating the latching means to release the control memberfrom each of its latched positions. I

13. In a control mechanism for a refrigerating machine, the combinationwith a driving motor element and a member driven thereby having limitedmovement relative thereto and means responsive to relative movementthereof, of a control device for direct actuation by said means, and acontrol device yieldably connected thereto.

14%. In a control mechanism, the combination with driving and drivenmembers having a slip connection therebetween and a member responsive torelative movement thereof, of a control device yieldably connected tosaid responsive member to be alternately biased thereby in a pluralityof directions, means for latching the control device in aplurality ofpositions, and thermo-responsive means. for releasing the latchingmeans.

15. In a control mechanism, the combination with driving and drivenmembers, having a slip connection therebetween and a member actuated inresponse to relative movement thereof, of a pivoted control arm havingopposite cam surfaces, a latch device for holding the control arm in twopositions, a yieldable member connected to said responsive member andadapted to engage said cam surfaces to bias the control arm away fromits latched positions, and thermoresponsive means for releasing thelatch de- 10 vice.

16.A control mechanism comprising a pivoted control arm having oppositecam surfaces, a double latch mechanism for l1olding the arm in twopositions, means for biasing the arm away from its latched positionsincluding a portion adapted to alternately engage said cam surfaces andthermoresponsive means for releasing the latch mechanism.

In testimony whereof, I have hereunto subscribed my name this 13th dayof March, 1922.

CHARLES THOMAS MASON.

